Angularity indicator for grinding crankshafts



April 22, 1947.

P. F. KOEBBE ANGULARITY INDICATOR FOR GRINDING CRANKSHAFTS Filed April 4, 1945 FHL/L F. HUE/55E @M @m f 0%4 Patented Apr. 22, 1947 s `PMEN'I OFFICE AN GULARITY INDICATOR FOR GRINDING CRANKSHAFTS Paul F. Koebbe, Jackson, Mich.

ApplicationApril 4, 1945, Serial No. 586,589

4 Claims.

in centering and set-up gauge apparatus particularly adapted to crankshaft grinding equipment.

It is an object of the present invention to provide an improved centering and set-up gauge for crankshaft grinders in which an indicator gauge has been permanently associated with the work rest. f

l.Another object is to provide an improved cornbination work rest and indicator.

A further object is to provide a combined work rest and indicator gauge for grinders especially adapted for centering and setting up crankshafts having the crank pins located at 90 or 120 to each other. Y

These and other objects' and advantages residing in the combination, construction and arrangement of parts will be more fully understood from a consideration of the following specification and attached claims.

v `In the drawings,

. Fig.` l is a side elevational view illustrating my combination steady rest and indicator as viewed in side elevation in crankshaft grinding,

Fig. 2 is a fragmentary enlarged side elevational view of a portion of the construction shown in Fig; 1, with parts thereof shown in vertical cross section, and

Fig..3 is a side elevational View of a modied formof vshoe' construction.

Itis standard practice in the grinding of crankshaft bearings to chuck the same in such a position that it will rotate about the axis of the bearing 'being ground. Line bearings present little difficulty in setting-up and gauging. Connecting rod bearings present an entirely different problem', especially where the throws of the crank are disposed at 90 or 120 to each other. Employing standard methods, considerable time is consumed` in setting-up and gauging in going from one connecting rod bearing to the next to assure each bearing is being ground on the proper axis of rotation.

The present inventionfhas been carried out in connection with the work or back rest I vadjustably supported through bolts I2 for axial movement along the table-I4 of the crankshaft grinding machine. While the invention has been adapted to a "Landis 22" x 72" regrinding machine, the, principles are not .thus limited in this application.

shown in Fig. 1, the crank pin I6 of the crankshaft I8 is supported at its ends in the usualchuck (not shown) for rotating the pin I6 around its center. The grinding Wheel'20 isv ro- The present invention relates to improvements K tated in the direction indicated by the arrow. To

steady the pin I6 against the action of the grinding wheel 20, shoes 22 and 24 denne aback rest. Thevshoe 22 is carried upon an axially slidable plunger 26 while the shoe 24 is carried by a swinging jaw 28 pivoted upon a stud 30. A threaded stop 32 adjusted in and out through the knob 34 regulates the angularity of the jaw 28 and the location of the shoe 24.

Referring to Fig. 2, the plunger 28, which is freely slidable in the bore 36, has a at ,axially extending spot 38 which is engageable by the nose of the thumb screw 40 to prevent rotation of the plunger 26 yet permitting axial movement. Coaxial with the bore 36 is a second bore 42 to receive a threaded bushing 44 held in position by the set screw 46. A threaded shaft 48 is adjustably threaded in the bushing 44 with one of its functions that of providing an adjustable abutment at 50 forv the inner end 52 of the plunger v26. A knurled jam nut 54 locks the sha-ft 48 in the nut 58 and axially adjusted by turning withv the set screw 62 preventing relative rotation between the housing and the nut 58 in desired positions of adjustment.

A dial indicator 64 of standard construction is shown mounted in the housing 00, being held in position by a set screw 66. The axially movable plunger 68 abuts the slidable piston 10 located in the bore 1I urged to the right by the spring '12. As shown, the piston 'I0 has a conical recess at 14 to receive a conical headed abutment I6 threaded upon the end 'I8 `of the rod 80. A thumb screw 82 acts as a set screw between the abutment 16 and end 18, as well as a means for withdrawing the rod to the left against the tension of the spring 12./ To this end, the screw 82 extends through an L -shaped slot having an `axially extending leg 84 and a transversely extending leg 86 providing a shoulder 88 back of which the shank of the screw 82 may be carried to lock the rod 80 in a withdrawn position.

The outer end 90 of the rod 80 freely slides in a bushing 92 and is reduced at 94 to carry a hard. ened end 96 which engages with the crank pin I 6 through a central opening 98 in the shoe 22.

In the modification shown in Fig. 3, the plunger 2B' is axially adjustable in the back rest I0 and carries a vertically slotted shoe 22. Supported on the pin I 00 is a bell crank lever I 02 which swings in the vertical slot of the Vshoe 22'. The upper end |04 of the lever |02 has a hardened boss |06 adapted to ride upon the surface of the crank pin I6' for the crankshaft I8. The indicator rod 80 has a reduced end 94 which in its advanced position engages the end |04 of the lever |02 and swings the same to bring the boss into engagement with the pin I6'. When the rod 00 is withdrawn, the lower end |00 of, the lever E02 is' heavy enough. to swing the end I 04 counterclockwise back against the shoulder IIO of the vertical slot in the shoe 22. In this position the boss |06 is out of contact with the pin I6 being ground and only the outer face H2 of the shoe 22 engages the pin I6'.

The present invention is particularly adapted to the regrinding of crankshafts which have been in service. To permit the threaded shaft 48 to be threaded in and out to change the location of the abutment end 50, a knurled nut H4. is xed thereto. By adjusting the abutment 50, the location of the shoe 22 relative to the pin I6 can be changed. As the housing 60 Will rotate with the shaft 4S, by having graduations |I6 thereon divided into thousandths of an inch, accurate regulations of the location of the abutment 50 can be made. Further, by having the lead of the threads on the shaft 48 and the outer thread on the nut 53 the same, the graduation III` will also serve to indicate the rate of advancement if adjustment. between the housing |50v and the nut 58 is desired to. bring the limits of movement of the indicator' rod 80 within the limits of the indicator 04 which usually does. not exceed .250. It will be understood that it. is only necessary that the end 90 of the indicator rod 80 project a slight distance beyond the outer face H6 of the shoe 22 in order to function as a centering and set-up gauge.

T'o compensate for wear of either the end 96T of the rod S0 or the shoe 22, by loosening the set screw 62 the rod 00 may be screwed into or out of the abutment 16.

In using the above discussed apparatus for centering and set-up in regrinding worn crankshafts, the end 96 of. the indicator rodv 6.0 may project as much as .100" beyond the face I I8 of' the shoe 22 without any chance of injury to thev indicator. By loosening the set screw 62, the housing 60 may be screwed in or out on the nut 58 to provide the right amount of tension on the spring l2 to keep the rod 60 at its end 9,6 against the crank pin I6.

It is important to note that regardless. of thesize crank pin being ground that the distance. between the face of the shoe 22. and the indicator mechanism never changes except for the wear of the shoe 22 which is extremely slight.

To describe a typical use of theaforesaid apparatus in regrinding a worn crankshaft, starting with the most badly worn crank pin, the same is centered for rotation about its longitudinal axis and with the pin i6v snug against the face IIS of the shoe 22., as: well as the shoe 24', the crank pin I is ground undersizeY forV example .020"` rEhe screw 2 is then removed from behind the shoulder 60 to permit the tension of the spring 'I2 to urge the end 90 of the indicator rod 80' into engagement with the surface of the finished groundr pin I6. To. simplify the reading of the. indicator dial, the screw 62. can be loosened; and the housing 60 adjusted so the dial reads zero plus .005" to .010 with the end 96' in con-` tact with the finished pin. Locknut 54 is then loosened and the housing 60 and shaft 48 are then rotated in a backing off direction until the dial reads zero minus .010 or one-half the amount ground oif the finished crank pin. This is also the amount ofthe movement of the abutment 50 and the plunger 26 and shoe 22 will slide inwardly a corresponding amount. The locknut 54 is then tightened, Thereafter the crankshaft carrying fixtures are locked and the chuck loosened just enough to permit the crankshaft to turn in the chuck. The back rest I0 is then loosened by sliding the draw bolt I2 and the back rest is slide axially along the table I4 to the next crank pin I6 to be ground and upon finishing secured to the table I4. The crankshaft I6 is then rotated until the pin I6 to be ground touches the shoe 22. To obtain the nal grinding position, the crankshaft is moved away from the shoe 22 until the indicator dial reads zero. The chucks are then tightened, the crank-y shaft carrying lxtures are unlocked, and the crankshaft is rotated. There is now .005 to .010" clearance between the shoe 22 and the pin I6 to be ground. This is a safeguard for Variation. in length of stroke. The crank pin is then centered through use of the indicator and the rod 60 is withdrawn by latching the screw 82 behind the shoulder 05 and the bearing is ready to be reground.

Havingv thus described my invention, what I. desire to cover by Letters Patent. and claim is:

1. A combination steady rest and indicator for grinders and the like comprising a shoe engaging with and giving support to the work, an indicator rod extending through said shoe, an indicator connected to said rod at a point remote from said shoe, and means to withdraw and hold said indicator rod in an inoperative position.

2. A combination steady rest and indicator comprising a main supporting structure, a plunger slidably supported in said structure for axial adjusting movement', a shoe supported from the outer end of said plunger, a shaft adjustable in said structure and disposed in axial alignment with said plunger, said plunger abutting one end' of said shaft whereby said shaft constitutes an adjustable abutment limiting the axial movement of said plunger, an indicator supported on said shaft, an indicator rod extending through said shaftr and plunger to a point. adjacent the outer face of said shoe, an indicator supported on the end of said shaft remote from. opposite said. abutment end, and an operative connectionA justment. toward and from the crank vpin andcarrying' said shoe on its outer end, anindicator, means for supporting said indicator in fixed relationship to said shoe in all positions of axial. adjustment of saidr shoe with reference to said crank pin, and an indicator rod extendingv from said shoe to said indicator, said rod having an end portion adapted to` engage said pin to facilitate centering; and setting-up of. the: crank pin fork grinding.

4. A combination steady rest and indicator for grinders and the like, comprising a shoe engaging with and giving support to the work, a slot in said shoe, a member pivoted on said shoe to move relative to said shoe in said slot, an indicator rod engaging with the back side of said member to 5 project said member toward the Work, and an indicator connected with said rod at a. point remote from said shoe.

PAUL F. KOEBBE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

